import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 26727
 * Date: 2024-01-17
 * Time: 17:10
 */
public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        //处理多组数据
        while(scanner.hasNextLine()) {
            String str = scanner.nextLine();
            String ret = func(str);
            System.out.println(ret);
        }
    }
    private static String func(String str) {
        boolean[] flag = new boolean[127];
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < str.length();i++) {
            char ch = str.charAt(i);
            if(flag[ch] == false) {
                sb.append(ch);
                flag[ch] = true;
            }
        }
        return sb.toString();
    }
}
